Robert Mugabe, addressing ruling party supporters at the Mahusekwa Stadium south-east of Harare, Zimbabwe, on March 5 2008. Photograph: Bishop Asare/EPA

Sitting in his office beneath a portrait of himself, Robert Mugabe cut a lonely, pitiful figure in his first in-depth interview for nearly 30 years, moved to tears at the memory of his lamented friendship with the Queen. Moments later, however, his eyes sparked with anger, betraying his vengeful nature.

The 84-year-old Zimbabwean President was talking to author Heidi Holland, and her 'psycho-biography' depicts a deluded leader who still has the power to bring everything right for his country - on condition he gets a phone call from Downing Street.

'His issue is with Britain,' said Holland, whose book, Dinner With Mugabe, has just been published by Penguin South Africa. 'Even today, he sees the white farmers as British. Given the history and the behaviour of Britain, there is logic - a twisted logic - to his thinking. It's all very well for Britain to say he is beneath contempt. But it is they who have to talk to him if the crisis is to end.'

Holland, a white Zimbabwean living in South Africa, spent 18 months lobbying for the interview, which she finally obtained in December. 'I had been waiting in Harare for five weeks and had been vetted and grilled. In the end I received a call telling me I should be at State House in half an hour. I arrived at 10am and three hours later His Excellency - "HE" as everyone calls him - received me.'

Holland's only previous meeting with Mugabe was in 1975 when she cooked for him at a clandestine dinner in Salisbury (now Harare). When he left, it was to go to Mozambique to lead guerrillas fighting Rhodesian white rule. He became Prime Minister in 1980. To write her book, Holland talked to three psychologists. 'I needed help in understanding how events in Mugabe's life, including his childhood, had impacted on his internal narrative.' By the time Mugabe was 10, his father had left home and his older brother had died. 'Mugabe has a thin skin and shaky self-image. When rejected or humiliated, he turns to revenge. His relationship with the British government has the intensity of a family feud.'

Holland saw evidence of Mugabe's ire whenever she hit on controversial subjects such as the Gukurahundi (the killing of up to 30,000 Ndebeles in the Eighties). He told her: 'Gukurahundi, what was it? You had a party with a guerrilla force that wanted to reverse democracy. And action was taken. And, yes, there might have been excesses, on both sides. There is no regret about the fact that we had to defend the country. But excess, where it happened, yes. Any death that should not have happened is a cause for regret.'

When Holland suggested that the economy was failing, Mugabe angrily insisted that it was 'a hundred times better' than that of most African nations. 'Outside South Africa, what country is like Zimbabwe?' he said. 'Even now, what is lacking now are goods on the shelves, perhaps. That's all. But the infrastructure is there. We have our mines, you see. We have our enterprises. We don't even have to go two years. Look at what we will do next year, and you'll be surprised.'

Some interviewees told Holland that the land invasions that began in 2000 and have deprived hundreds of whites of their farms may have been initially supported by Mugabe but got out of hand. 'He denies this, of course,' says Holland. 'But what is most interesting is that... he really thought the British government would do something.'

But Britain, under Tony Blair, proved the equivalent of a disappointing parent, quick to scold and unwilling to listen. When the Labour government made it clear it felt no obligation to subsidise further programmes of land acquisition because previous compensation had been misused, Mugabe went ballistic. 'He was nearly crying when he told me that Blair "even poisoned Prince Charles and the Queen against me".

'I think he granted me the interview because he feels he is getting old and it's time to put certain things on the record. But he expects to win the election and probably will.'

Asked how he would like to be remembered, Mugabe said: 'Just as the son of a peasant family who, alongside others, felt he had a responsibility to fight for his country and was grateful for the honour that the people gave him in leading them to victory over British imperialism.'